(CNN) -- Pop culture almost portrays it as if there's one around every corner these days: a cougar -- an older woman looking to latch onto a younger man.

Demi Moore and Ashton Kutcher -- 15 years her junior --are the Hollywood poster couple of the modern phenomenon of a successful, established woman choosing a "boy toy" for herself.

The ABC sitcom "Cougar Town" tells the story of a divorcee real estate agent who returns to the dating world while raising a teenage son. Along the way, she keeps the company of a number of younger men.

The "cougar theory" is based on the notion that with a greater prevalence of female financial independence, women are now free to target men of any age group, rather than trying to secure financial security from older, wealthier males.

So everyone's doing it, right? Or, at least it's a growing trend.

Not so fast, says Michael Dunn, a psychology professor at the University of Wales Institute, Cardiff, who led a study that analyzed the age preferences of 22,000 men and women using online dating sites across more than a dozen cultures, including Christians and Muslims.

"Although there was some cultural variation in extremes, the results showed clearly that women across all age groups (20, 25, 30, 35, 40, 45, 50) and cultures, targeted males either their own age or older," according to Dunn, who said a much different pattern was evident in men.

"Younger men (20-25) either targeted females their own age or marginally younger," Dunn said. "However, as males aged, they clearly expressed a preference for women increasingly younger than their own age ..."

The results support theories long backed by social anthropologists.

"These findings are clearly supportive of evolutionary theory. A wide variety of evidence has shown that women, when considering a potential long-term partner, focus more than males on cues indicative of wealth and status, and these logically accumulate with age," Dunn said.

"Males conversely focus more intently on physical attractiveness cues and these are clearly correlated with the years of maximum fertility."

So, while cougars remain the stuff of Hollywood and pop culture lore, these felines still have a way to go before their hunt for young cubs rules the jungles of the dating world.